There is conventionally known a ship collision preventive aid apparatus of the type above-mentioned having a cathode-ray tube ( hereinafter referred to as CRT ) for displaying a radar picture, a display means including a detector means for processing the radar picture to detect movements of other ships, and an operation means including a plurality of per-function operation switches, a track ball or a joy stick for adjusting the cross mark setting position, a variable range marker, an electronic cursor adjusting dial, and an indicator for displaying the positions, courses and speeds of own ship and other ships.
Based on the operation and setting of the operation means, the radar picture displayed on the CRT from one minute to the next is processed in the detector means to detect the movements of other ships.
On the CRT screen, there are displayed collision preventive aid data of a cross mark, a suppression zone or other to be discussed later, and also collision preventive aid data of the courses, speeds or the like of other ships. On the radar screen, alarm marks are also displayed as overlapping on or adjacent to the images of other ships which are in a great danger of collision with the own ship on the radar screen.
For example, when a target ship is to be manually acquired to display a cross mark, a target manual acquisition operation switch of the operation means is turned ON to display, on the radar screen, a cross mark for designating a target to be acquired. By operating the joy stick or track ball, the cross mark is moved onto the image of the target ship which is in a great danger of collision with the own ship. With such operation, the target ship to be acquired is displayed together with display of the data of the target ship such as the position, course, speed on the indicator of the operation means.
For setting and displaying a guard zone, a guard ring setting operation switch of the operation means is turned ON, and the variable range marker is then adjusted to set a guard ring having a desired radius. With the desired guard ring set and displayed on the radar screen, an alarm is adapted to be given when other ships enter the guard zone. The operator is thus informed of access of other ships.
For setting and displaying a suppression zone, a suppression zone setting operation switch of the operation means is turned ON, and the electronic cursor adjusting dial is then operated. On the radar screen, there are set and displayed two suppression lines by electronic cursors having a desired crossing angle and located symmetrically with respect to the stem direction, so that a suppression zone is set and displayed outside of the suppression lines. At this time, only the data such as courses and speeds of other ships outside of the suppression zone are detected by the detector means, and only other ships outside of the suppression zone are subjected to acquisition and tracking.
For setting and displaying a safety fairway for the own ship, a fairway setting operation switch of the operation means is turned ON and the electronic cursor adjusting dial is then operated. On the radar screen, there are displayed two fairway lines by electronic cursors to set and display a fairway bordered by these two fairway lines.
According to such arrangements, the CRT, the display means and the operation means are independently disposed, thereby to render manipulation very complicated to disadvantageously reduce the working efficiency.
Moreover, when setting and displaying collision preventive aid data such as a cross mark with a joy stick or a track ball, accurate fine adjustment cannot be made, thereby to reduce setting accuracy to provoke erroneous manipulation. Thus, there is a great danger of serious accidents occurring.
Furthermore, such separate arrangement of the CRT, the display means and the operation means causes the apparatus to be constructed in a complicated manner and in a large size.